Cylinder lock



Dec. 24, 1940. H MACHNST 2,225,703

`CYLINDER LOCK Filed April 3, 1939 gli mwfof Patented Dec. 24, 1940 ,UNITED STATES CYLINDER LOCK Harold Machinist, i Chicago, Ill., assignor to Dudley Lock Corporation, Chicago, Ill., a corporation of Illinois Application yApril 3, 1939, Serial N0. 265,627

4 Claims.

This invention relates to cylinder locks,` and its object is to provide protective armor for the exposed portions of the lock, which shall be strongly resistant to cutting or drilling tools,

and which is so connected to the parts of the lock itself as to offer no means for eifectively' gripping or engaging the said parts in an attempt to Wreck the lock or to loosen it from its anchorage in the closure which it controls. The invention consists of certain features and `elements of construction in combination, as herein shown and described and as indicated by the claims.

In the drawing:

Fig. 1 is an end or face View of a lock bodying this invention.

Fig. 2 is a side elevation partly in section. k

Fig. 3 is a perspective view of the casing with the protective parts disassembled therefrom and arranged in the order of their replacement.

'I'he drawing shows the lock casing I as comprising a cylindrical body threaded throughout most of its length and having flattened areas 2 at opposite sides, which may be understood to interlock with straight portions of a suitably formed aperture in the door or other closure to which the lock is applied. A shoulder 3 will normally seat against the outer face or surface of the closure, and any suitable securing nut, not shown, Will be applied to the threads of the cylinder I so as to clamp against the opposite or inner face of the closure to secure the lock in operative position therein. Within the cylinder 2 there is provided a lining member 4 which may have suitable slots or apertures for interengagement with the usual tumblers of the key plug which is rotatable within the lining, and which terminates inwardly in a squared or otherwise non-circular spindle 5 to which the operating crank arm or cam is secured for inter-engagement with a locking bolt or latch to be operated by the lock mechanism.

The shoulder 3 is one surface of a head flange 1, formed integrally on the outer end of the casing I. The lining sleeve 4 which is suitably anchored against rotation in the casing I terminates at a little distance back from the outer face of the head flange 1 providing a recess into which there is tted an end cap 8 of special armor steel to protect the key plug. The end cap is rotatable in this recess of the head flange 1 and is held in place by a retainer plate 9 having lugs 9a which engage notches 1a. The end cap 8 includes a suitable key slot Iia formed with Wards 8b to inter-member with the proper type (CI. 'Z0-417) of key for the lock, and this slot extends through a central projection Ilc whose outer face 8d is of concave form to facilitate entering the key. The 'retaining plate 9 is formed with a central bore 9c in a thickened annular portion 9d of the plate 5 which immediately surrounds the central projection 8c of the end cap, and Within which the latter is rotatable with the key plug.

'Ihe assembled end cap 8 and retaining plate 9 t into thevrecess in the end of the head flange 10 1 of the casing, but with the thickened portion 9d projecting beyond the outer face of the head iiange. And these parts are finally locked in position by means of a head ring I0 which ts snugly but rotatively around the cylindrical sur- 15 face of the ilange 1 and includes a front wall IIIa which overlapsv the thinner peripheral portion 9b of theV retaining plate 9.l A central aperture Illd admits the thicker portion 9d of the plate 9 so that the latter extends substantially ush with the outer face of the head ring. The cylindrical surface of the iiange 1 includes a groove 1x and the .opposite surface of the head ring I0 includes a groove IllX so that when the head ring is applied to the iiange 1 a split locking ring II of spring steel, and preferably of rectangular cross-section, may be lodged in the groove 1x and permitted to expand so as to extend partly into the groove Illx as the head ring I0 is slipped into place. Thus thehead ring is permanently secured on the flange 1 but with capacity to rotate freely thereon.

It should be understood that not only the end cap 8 but also the retaining plate 9 and the head ring I 0 are formed of suitable alloy, preferably in the nature of armor steel, which is too hard to be cut by ordinary tools, such as drills, files or saws; accordingly, with the head ring and other parts in place over the end of the casing I the casing and the key plug within it are protected from any outside attack of this nature. Preferably, the periphery of the head ring I II is inclined or beveled at IIlb to provide a suitably designed finish for the lock, and this beveled formation also renders it particularly diiiicult to secure a grip on the head ring by means of a wrench or other tool. And, infact, since the head ring I0 is freely rotatable upon the flange 1 the application of a Wrench or any other gripping tool to the ring would be futile for the purpose of attempting to rotate or twist the casing 1 to loosen it from its anchorage in the closure. The construction, therefore, effectively prevents tampering with the lock by thieves or mischievous persons, and adds measurably to the security Which the lock provides.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that variaus modifications and re-arrangements of the parts may be made Without departing from the spirit and scope of the invention, and that the same is not limited to the particular form herein shown and described, except in so far as indicated by the appended claims.r

I claim:

1. In a cylinder lock, a casing for supporting a rotatable key plug, an end cap of armor steel rotatably disposed against one end of the casing to cover the end of the key plug, and a head ring formed to cover the peripheral and outer4 end surfaces of said casing and retaining said end cap in place, said head ring being freely rota-table on the casing and being provided with means inaccessibly disposed withinthe ring and inter-engaged' With the casing to retain the ring thereon.

2. In a cylinder lock, a casing for a rotatable key plug, the end of the casing having a recess, an end cap of armor steel rotatably disposed in the recessl to cover the end of the key plug, a retaining plate formed with a central aperture smaller than said end'cap, said plate marginally overlapping said cap and being held against rotation by inter-engagement with the casing, and a head ring freely rotatable on the casing and formed to cover the peripheral and outer end surfaces thereof and overlapping the retaining plate, together With means inaccessibly enclosed by said ring and inter-engaged with the ring and the casing to retain the ring thereon and secure the end caprand retaining plate in position.

3. In a cylinder lock, a casing for a rotatable key plug, an end cap of armor steel rotatably disposed at one end of the casing -to cover the end of such key plug, said cap having a key slot to register with that of the plug for admitting a key thereto, a retaining plate formed with a central aperture smaller than said end cap and disposed with the marginal portion of the aper ture overlapping the cap, said plate being held against rotation by inter-engagement', With the casing and the rim of its aperture having a notch to admit the key for inter-engagement of the latter with said rim when the key is rotated, and a head ring freely rotatable on the casing and formed to cover the peripheral and outer end surfaces thereof and overlapping the retaining plate, together With means inaccessibly enclosed by said ring and inter-engaged with the ring and the casing to retain the ring thereon and secure the end cap and retaining plate in position. v y

4. In a cylinder lock,\a casing for a rotatable key plug, the end ofthe casing having a recess, an end cap of armor steel rotatably disposed in the recess to cover the end of the key plug, a retaining plate formed With a central aperture smaller than said end cap, said plate overlapping the marginal portion of the cap to retain it in the recess, said plate having radially extending lugs and the end of the casing having notches to receive said lugs for holding the plate against rotation, and a head ring freely rotatable on the casing and formed to cover the peripheral and outer end surfaces thereof and overlapping the retaining plate, together with means inaccessibly enclosed by said ring and inter-engaged With the ring and the casing to retain the ring thereon and secure the end cap and retaining plate in position.

l HAROLD MACHINIST. 

